Hi guys I am currently trying to improve my rendering and lighting abilities and want to use this photo as a starting point
I have created an object and some lights already using Maya Mental Ray and wanted to ask what I need to consider next in replicating this image. Do I need to add an ambient occlusion pass or should mentalray indirect lighting provide enough ambient shadows? Also I'm not sure if my colouring of the object is off or if I can get the wood looking more similar by adjusting my lights.
Any recommended reading materials or tutorials would be greatly appreciated.
P.S. I noticed when trying to render the same 3d wood texture in Vray I seemed to get completely different patterns that didnt reflect how the texture was being displayed in MR. Is there a reason for this?
Replies
You should also look up linear workflow. From the look of it looks like you'r rendering in sRGB space.
HDR is not needed.
I did this scene to demonstrate for another thread just yesterday. To mimic your reference, the set up can be very similar. You only need 1 light, make it large and light it from slightly higher angle. Place a white plane on the opposite side to help reflect the light back.
Your specular value should be 1.5 if using IOR. If using a range from 0-100 or 0-1 use 4.0 or 0.04 respectively. This is a sufficient approximate for the reflection of dielectric materials. Another, and more important, question is what kind of material setup are you using? This plays a large part in how you're going to achieve realism. You could likely be applying fresnel when it's already doing it for you.
I tried to reproduce it, as already said on the thread, you just need a single light on the left.
GI+AO
Are you using Global Illumination?
@Eric + SonicBlue - Thanks so much for your corrections. SonicBlue your render is amazing! I have tried a new render with your lighting but couldnt get as good a result. Not sure where I'm going wrong as I still have a lot to learn. I have attached my render settings and the result below. I am using GI but not AO
This is Maya 2016 mental ray with the new GI algorithm, the result is not good as Cinema 4D, but I'm not comfortable with mental ray and Maya. I couldn't figure out how to improve shadow samples to increase the quality, the new render options layout doesn't help neither.
From what I can see from your screenshots one of the main problem is the material, it doesn't have reflections and the specular colour is wrong.
In this render I used a mental ray material with a texture loaded into the colour slot.
Another probable issue is from the light, you probably haven't selected the Decay type, photorealistic lights have an Inverse Square decay, in Maya it's called Quadratic.
What you can do now is scrap the material you have, assign a new way without changing the colour but try to mimic how the surface reacts, before loading a texture, so that you don't have to manage too much parameters at the same time.
Then you should position the light to get the desired result, if you enable the Quadratic Decay, you have to increase the light Intensity a lot, in my case I used 2500.
Start simple, by trying to get the same light effect as the reference, when you have the correct lighting you can start to add details to the object.
For now here is a quick screen grab of my current fiddling around(I tried a new texture and material) Thanks again for all the help!
Maybe I've found why the shadows were that grainy, I had to enable the Area light to be a mental ray light, and change the subdivisions from there.
mental ray is a quite complicated software, not only it have a series of parameters scattered around various panels, but it also uses particular shaders to do some specific operations. I would use V-Ray over it, is it more understandable, but if you want to know more about mental ray, there are those video series from Jeremi Birn (who happens to work for PIXAR, I know him from an old Softimage|3D tutorial):
https://vimeo.com/user895130
There is the official NVIDIA mental ray blog
http://blog.mentalray.com/
other stuff:
http://wiki.bk.tudelft.nl/toi-pedia/Rendering_Mental_Ray:_Global_Illumination
http://www.3dm3.com/tutorials/maya/mr/
http://www.zbrushcentral.com/showthread.php?83524-Make-it-look-real-%28With-mental-ray%29
An already made studio setup:
http://23d.one/maya-studio-setup/
CGSOCIETY Lighting Challenges thread:
http://forums.cgsociety.org/showthread.php?f=185&t=319005
so that if you want, you can grab some scene files and compare your render with other people works.
There's also this:
http://forums.cgsociety.org/showthread.php?f=87&t=922792
@DireWolf I am using linear workflow most of this point but I may have missed activating it on the texture this time
@sonicBlue Thank you so much for these tips! I am actually more inclined to work with Vray as I've seen far more positive results with other people. I think I will try to render it out using Vray. I just happen to know a small bit already about MR. Thank you for the links. I had a quick look and already the lighting challenge seems great! Hopefully I can update this thread soon with a Vray version of this scene